The present invention relates to a photoelectric module device, and especially to a photoelectric module device that overcomes the prior art problem of the packaging material of the photoelectric module device permeating into the terminal holes of the substrate.
In a prior art photoelectric module device, for example, an infrared data transmission module (IrDA), a light emitting diode, a charge coupled device (CCD), etc., an electrically connected terminal (welding point) protrudes out from a lateral side, and therefore the device has a large volume. However, the compact design of electronic products is a current trend. For example, in an infrared data transmission module, in order to reduce the volume, an encapsulating method is used in packaging. However, such a method is likely to induce poor positioning of the chip in the module. For example, in the process of packaging, the buoyancy force due to the liquid resin will induce the photoelectric module device chip to shift its position away from the center of an optical axis, so that the yield ratio for manufacturing the devices will decrease.
In order to correct the above discussed problem, another prior art infrared data transmission module 700 has been disclosed. Referring to the design of FIG. 6, a lower circuit board 70 is provided with a solder mask 72 for preventing resin from being filled into the terminal holes 71 during encapsulating. Furthermore, the photoelectric module device chip 76 is installed on the circuit board 70 and an electric connection is formed therebetween. Then a packaging layer 74 is formed by injection molding. Although this prior art system uses a solder mask 72 to prevent resin from filling into the terminal holes 71, it cannot sustain the high temperature and high pressure of injection molding. As a result, the solder mask 72 often breaks during injection molding, so that resin flows into the terminal holes 71, and thus, the product is ineffective and the yield ratio is reduced.
FIG. 7 shows a perspective view of a prior art LED chip 800 which has a plurality of terminal holes 81 extending from the lower layer circuit board 80 and the upper package layer 84. FIG. 8 is a perspective view of a prior art charge coupled device 900 (CCD) which has a plurality of terminals 91 and an upper packing layer 94. A charge coupled device chip 97 is on a lower substrate 90. The chip 97 is connected to the inner legs of the terminals 91 through respective conductive wires 95. The defects of these products is the same as the above product, i.e., the terminal holes 81 and terminals 91 of the lower circuit board 80 and substrate 90 protrude from a respective lateral side thereof, so that the volume of the products are large and cannot be reduced.
Accordingly, the primary object of the present invention is to provide a photoelectric module device that resolves the prior art problem of the packaging material of the photoelectric module device permeating into the terminal holes and further to improve the manufacturing yield ratio for the device.
Another object of the present invention is to provide a photoelectric module device that resolves the prior art problem of the photoelectric module device having an overly large volume.
Still another object of the present invention is to provide a photoelectric module device which has a simple packaging process and thus lowers the cost thereof.
In order to achieve above and other objects, the present invention provides a photoelectric module device comprising a multiple layer printed circuit board and at least one photoelectric element, such as a light emitting diode chip, photo diode chip, phototransistor chip, charge coupled device chip, etc. The multiple layer printed circuit board has at least an upper circuit board substrate, a lower circuit board substrate, and a circuit. The photoelectric element is installed on the multiple layer printed circuit board and is electrically connected to the circuit. By injection molding a transparent resin, the photoelectric element is packaged above the multiple layer printed circuit board. The lateral surface of the lower circuit board has a plurality of terminals which are electrically connected to the circuit board for electrical connection to external devices. Each terminal is formed on an inner wall of a through hole on the lower circuit board substrate by plating. The inner wall is partially cut away during cutting of the printed circuit board. The remaining portion thereof becomes the terminal. Further, the upper circuit board substrate serves to seal the through holes before cutting, for preventing resin from permeating therein during injection molding.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when reading in conjunction with the appended drawings.